Electrophysiotherapeutical apparatus



Dec. 5, 1939. 1 DOBERT 2,182,223

ELECTROPHYSIOTHERAPEUTICAL APPARATUS Filed Sept. 5, 1936 2 Sheets-Sheet l 5, 1939. .1 H. DOBERT ELECTROPHYSIOTHERAPEUTICAL APPARATUS Filed Sept. 5. 1956 2 Sheets-Sheet 2 Patented Dec. 5, 1939 UNITED STATES PATENT OFFiCE ELECTROPHYSIOTHERAPEUTICAL APPARATUS 15 Claims.

This invention relates in general to electrophysiotherapeutical apparatus, and has more particular reference to multi-form energy supply sources for supplying various modalities of electrophysiotherapy to patients.

The invention has as an object, the provision of a novel low voltage multi-wave apparatus which at the will of an operator, and by the manipulation of simple controls, will produce galvanic current for its thermal and chemical effects, sinusoidal current for muscular stimulation and action, and various modifications of either galvanic or sinusoidal currents and combinations thereof for use in electrotherapy.

Another object of the invention is the provision of such therapeutical apparatus which may be aptly described as thermionic as distinguished from electrotherapeutic apparatus employing vibrating or other mechanical devices for generating a desired modality, or for converting current of a usual or predetermined wave form into current of a desired wave form, whereby to obtain substantially noiseless operation, a minimum of maintenance, and a generally simplified and compact multi-wave apparatus.

Other objects of the invention will be apparent from the following description and from the accompanying drawings, in which similar characters of reference indicate similar parts throughout the several views.

Referring to the drawings:

Fig. 1 is a perspective View of an electrophysiotherapeutic apparatus embodying the features of the invention;

Fig. 2 is a detailed side View, partially in section. of a suitable selector to select the desired modality produced by the apparatus shown in Fig. 1;

Fig. 3 is an elevational View, partially in section, of a suitable relay employed as a control means in the novel apparatus;

Fig. 4 a schematic wiring diagram of the apparatus shown in Fig. 1; and

Fig. 5 is a schedule of the modalities and the corresponding positions of the selector for producing the same.

As illustrated in the drawings, a multi-wave electrophysiotherapeutic apparatus for accomplishing the foregoing objects may be provided with a suitable casing or housing having a pair of sockets II and I2, or other suitable patients or output terminals` which are electrically connectible to suitable applicators, not shown. The lterminals II and I2 may be carried at some convenient location about the casing, for example,

(Cl. 12S-420) by a control panel I3 at one side of the casing.

The control panel I3 is adapted to carry the various control and indicating devices for the multi-wave apparatus in the casing, including selector operating means I4 operable to select the desired modality to be supplied to the patients terminals II and I2, voltage control means i5 for varying the voltage applied to the sockets lI and I2, frequency control means I6 for varying the frequency of the current variations employed in certain treatments, a multi-scale meter I'I for indicating the current supplied to the patients terminals, a multi-point switch I8 for switching to the desired scale of the meter II, and a pair of lights or other suitable means I9 and 2l. for indicating the polarity and frequency of the output current.

Inside the casing, a selector is employed which is operatively connected with the selector operating means I4 to facilitate selecting the desired modality. Various types of selector may be employed for that purpose, a suitable type being a well known gang switch illustrated in Fig. 2. While the gang switch itself forms no part of the invention, it might be well by way of explanation, to point out briefly that it comprises a framework 22 which carries a plurality of spaced multi-point switches 23, 24, 25, 26, 2l, and 28, and a switch operating shaft 29 common to all of the switches and journaled in the framework 22. 1

The shaft 29 extends through the control panel I3 for operable connection with the selector operating means I4. Each of those switches includes a stationary contact carrying member 3i suitably Xed on stationary members of the framework, and a movable contact member 32 fixed cn to rotate with the shaft 29.

Each contact carrying member 3| has suitably secured thereon a plurality of stationary contacts arranged concentrically about the shaft 29 for electrical contact with the corresponding movn able contact member 32 as the shaft is rotated from the selector operating means I 4. The stationary contacts of each contact carrying member 3| are electrically grouped by electrical con- 4 nections whereby, as shown in Fig. 4, the switch 23 is an off and on switch provided with switch points or contacts 33 and 34; the switch 24 is provided with switch points or contacts 35 and 36; the switch 25 includes switch points or contacts 3l, 33, 39, and 4I; the switch 2S has switch points or contacts 42, 43, 44, 45, and 46; the switch 2l comprises switch points or contacts 4l, 4S, and 49, and the switch 28 is an off and on switch with switch points or contacts 5I and 52.

The selector gang switch is adapted selectively to make and break electrical circuits which, as diagrammatically shown at 53 in Fig. 4, may have a common source of electrical energy of, for example, 60 cycle alternating current for energizing the primary winding of a suitable transformer T, and which are adapted to convert the supply energy from the source 53 into the desired types of currents at the proper voltages, or into the desired modalities. The transformer T is provided with a secondary winding 54. That secondary winding, a suitable rectifier R, an electrical filter F, and an oscillator O, are arranged electrically as sources of alternating current, rectifled or pulsating current, galvanic or rectified and filtered current, and oscillating current, respectively. The rectifier R includes a thermionic tube V, the filament of which is heated or energized from a secondary winding 55 of the transformer T, and which is adapted to rectify the current from the secondary transformer winding 54. The filter F is electrically connected across the output of the rectifier R, for smoothing the pulsations out of the rectified current, and includes a choke or inductance coil 56 and a pair of condensers 51.

Connected across the output side of the filter F, are series connected resistors 58, 59, and 6|, and the oscillator O, the resistor 58 having terminals 58 and 59', the resistor 59 having terminals 59 and 60, and the resistor 6| having terminals 60 and 6I'. The oscillator O includes a thermionic tube V1 with a coupling transformer 62 having its primary winding 63 connected between the plate electrode of the tube V1 and the contact 38 of the switch 25, and its secondary winding 64 connected to the grid or control electrode of the tube V1 and to the terminal 59. The secondary winding 64 is shunted by a condenser 65 and the filament of the tube V1 is heated or energized by a secondary winding 66 of the transformer T.

The transformer T may be provided with another secondary winding 61 for heating or energizing the filaments of thermionic tubes V2 and V3 which serve as thermionic resistors in the production of modalities having certain` wavy characteristics The tubes V2 and V3 are associated with a relay preferably of the polarized type shown in Figs. 3 and 4, and having coils 68 and 69, a pivoted armature 1|, a contact operating member 'I2 operatively connected to the armature 1|, and normally closed contacts 13 and 14 and normally open contacts 'I5 and 16. A coil 68 is connected in parallel with a variable resistance 11 and between the plate electrode of the tube V2 and the contact 43 of the switch 26, the resistor 11 having a movable resistance varying member 18 connected to the contact 44 of that switch.

Like the coil 68, the coil 69 of the relay is connected in parallel with a variable resistance 19 having a movable resistance varying member 8|. The parallel connected coil 69 and resistance 19 are connected between the plate electrode of the tube V3 and the contact 41 of switch 21` and the resistance varying member 8| is connected to the contact 48 of that switch.

Between the movable contact members 32 of the switches 26 and 21 are connected resistors 82 and 83 having resistance varying members 94 and 85, respectively, operable by the voltage control means I5 and serving with the resistor varying members, as voltage dividers for varying the voltage applied across the patients terminals and I2. The resistance varying member 84 is electrically connected by a conductor 86 to the movable member of the multi-point switch I8. That switch I8, as shown in Fig, 4, is provided with a plurality of contacts that are electrically connected with the multi-scale current meter I1 which in turn is electrically connected by a conductor 81 to the patients terminal II. The contacts of the switch I8 are selectively engageable by the movable switch member for selecting the appropriate scale of the meter and connecting the meter in series with the resistance varying member 84 and the patient's terminal II, or for short circuiting the meter as desired.

The resistance varying member is electrically connected by a conductor 88 to the contact 35 of the switch 24, the movable contact member of which is connected by a conductor 89 to the patients terminal I2. The contact 36 of the switch 24 is connected by a conductor 9| to a terminal 92 between, and connected to, each of the series resistors 82 and 83. That terminal 92 is connected by electrical conducting means 93 to the movable contact member of the switch 25.

The light I9 is connected to the movable contact member of the switch 26 and to a common terminal 94 which is connected through a resistor 95 to the conducting means 93, and which is connected to the light 2 I. The other terminal of the light 2| is connected by electrical conducting means 96 to the movable contact member of the switch 28. The contact 5| of the switch 28 is connected by a conductor 91 to the movable contact member of the switch 21. Thus, the resistors 82 and 83 and the lights I9 and 2| are electrically arranged in parallelism.

In order to complete the plate circuits of the tubes V2, and V3, the filament of each tube is connected by electrical conducting means 98 to the terminal 60 between the resistors 59 and 6I. For controlling the current flow in those plate circuits, the grid or control electrode of the tube V2 is connected by a conductor 99 to a common terminal |0| of a bank or plurality of resistors |02 having their other terminals respectively connected to a plurality of contacts |03 which are selectively engageable by a movable contact member |04 operable by the frequency control means I6. Likewise, the grid or control electrode of the tube V3 is connected by a conductor |05 to a common terminal |06 of a bank or plurality of resistors |01 having their other terminals respectively connected to a plurality of contacts |08 which are selectively engageable by a movable contact member |09 operable by the frequency control means I6.

A condenser III is connected between the conducting means 98 and the conductor 99 by conductors |I2 and II3, and a condenser I|4 is connected by conductors I|5 and IIB between the conducting means 98 and the conductor |05. The movable contact member |04 is connected by a conductor ||1 to one of the normally closed relay contacts 13, the other contact of which is connected by a conductor II8 to a conductor I|9 that in turn is connected to a line conductor |20 connecting the center of the secondary transformer winding 54 to the terminal 6|. The conductor I I9 extends beyond its connection with the conductor II8 to connection with a resistor |2I, the other terminal of which is connected to the contact 49 of the switch 21. The conductors I|9 and |20 serve as a return or negative line conductor for either or both positive line conductors |22 and |23 extending respectively 'from one end terminal of the transformer winding 54 to the contact 46 of the switch 26, and from the output of the rectifier R to the input side of the lter F. A conductor |23' connects thc line conductor |23 with the contact 39 of the switch 25.

The conductor I i1 is connected by a conductor |24 to one of the normally open relay contacts 15, the other Contact of which is connected by a conductor |25 to the conducting means 98, The movable contact member |09 is connected by a conductor |26 to one of the normally open relay contacts 18, the other contact of which is connected by a conductor |21 to the conductor II9. The normally closed relay contacts 14 are connected by conductors |28 and |29 between the conducting means 98 and conductor |26.

A resistor I3I is connected by conductors |32 and |33 between the terminal 60 and the contact 42 of the switch 26. The conductor |34 connected at one end to the Contact 45 of that switch, and at its other end to a point between the plate of the tube V2 and the relay coil 68, may be employed to open circuit the parallel connected coil 68 and resistor 11 in the production of certain modalities.

As shown in the wiring diagram of Fig. 4, the selector comprising the switches 23 to 28, inclusive, is in the off position, in which, as will be seen by reference to the schedule constituting Fig. 5, the movable switch member of the switch 23 is in engagement with the contact 33 which is the off or open position for that switch. Hence, no energy is being supplied to the apparatus. The other contact positions of the various switches 23 to 28 in the selector, and the resp-ective modalities resulting therefrom, are shown from (a) to (j), inclusive, in Fig. 5, and the circuits for producing such modalities will now be traced.

(a) Galvamc By turning the selector operating means I4 through a predetermined distance, the switches 23 to 28 of the selector may be set in the positions indicated by a in Fig. 5. Such manipulation of the selector operating means completes a circuit which includes the secondary transformer winding 54, the rectifier R, and the filter F, thus impressing a rectied and filtered or substantially constant unidirectional voltage across the series resistors 58, 59, and 6| connected across the output side of the filter. A portion of that constant voltage is employed to energize a circuit extending from the terminal 59' through the contact 38 and movable member of the switch 25, the conductor 93, the terminal 82, the resistor 82, the light I9 and resistor 95 in parallel with the resistor 82, the contact 42 and movable member of the switch 26, the conductor |33, the resistor I3I, and back by way of the conductor |32. Thus a substantially constant voltage is impressed across the parallel connected light I9 and resistor 82, causing the light to glow.

A variable portion of that constant voltage may be impressed on the terminals |I and I2 whereby a patient connected thereto through usual connections will receive a substantially constant unidirectional or galvanic current, The applicator circuit thus includes the resistance varying member or voltage divider 94 operable by the voltage control means I5, the conductor 86, the switch I8 for selecting the appropriate terminal of the current meter I1, the meter I1 or its short circuiting terminal, and the conductor 81 to the patients terminal II; and the terminal 92, the conductor 9|, the contact 36 and movable member of the switch 24, and the conductor 89 to the patients terminal I2.

(b) Galvam'c wave This modality is obtained from a pulsating unidirectional voltage of relatively low frequency. In order to obtain this modality the selector operatng means I4 is manipulated to set the switches 23 to 28 in the positions indicated at b in Fig. 5. Thus a rectified and filtered or substantially constant voltage is impressed across thel series resistors 58, 59, and 6| as described above in connection with the modality referred to as galvanic. A portion of that voltage is employed to charge the condensers III and II4 alternately, depending upon whether the relay contacts 13 or the relay contacts 16 are closed. The charging circuit for those condensers eX- tends from the terminals 60 and 6I' of the resistor 6I and includes the conductor |I9 and either the conductor II8, the relay contacts 13, the conductor II1, the movable contact member |94, the selected contact |03 and resistor |02, the common terminal IOI, the conductor I3, the condenser III, the conductor II2 and the return conductor 98, or the conductor |21, the relay contacts 16, the conductor |26, the movable contact member |09, the selected contact |08 and resistor |01, the common terminal |05, the conductor II6, the condenser II4, the conductor II5, and the return conductor 98.

Thus, the condenser II I may be charged when the relay contacts 13 are closed and the condenser |I4 may be charged when the relay contacts 16 are closed. A discharge circuit is provided for each of the condensers III and II4. The discharge circuit for the former extends from one terminal of the condenser III to the common terminal IIlI by way of the conductor II3, and therefrom through the selected resistor |02 and contact |03, the movable contact member |04, the conductor II1, the conductor |24, the relay contacts 15, and back to the other terminal of the condenser III by way of the conductors |25, 98, and II2. The discharge circuit for the condenser II4 includes the conductor I|6 connected to one terminal of that condenser, the common terminal |06, the selected resistor |01 and contact |08, the movable contact |09, the conductor |26, the conductor |29, the relay contacts 14, and the conductors |28, 98, and II5.

It will be understood that when the relay coil 68 is energized the relay contacts 13 are closed (charging position for the condenser III), and the relay contacts 15 are open. At that time the relay contacts I4 are closed (the discharging position for the condenser II4), and the relay contacts 16 are open. When the relay coil 69 is energized, the relay contacts "I3 are open, the contacts 15 are closed (the discharging position for the condenser III), the contacts "14 are open, and the contacts 16 are closed (the charging position for the condenser II4).

will. be presently described. the relay coils 68 and 59 are alternately energized and alternately deenergized. whereby the relay contacts 13 and 16 are operated for charging the condenser |I| while the condenser I|4 is dischargand for discharging the condenser I |I while the condenser Elfi is charging. As will be seen by reference to Fig. 4, the grid or control electrode of the tube V2 is connected to the charging and discharging circuits of the condenser III at the common terminal |I of the resistor |02 by the conductor 99. Likewise, the grid or control electrode of the tube V3 is connected to the charging and discharging circuits of the condenser II4 at the common terminal |06 of the resistors |81 by the conductor |05. In that manner, a pulsating voltage may be impressed on the grids of the tubes V2 and V3 alternately, and the rate or frequency of those pulsations may be varied by varyingthe charging and discharging rates of the condensers and II4. That is accomplished by the operation of the frequency control means I6 for adjusting the movable contact members |04 and |99 to select the resistors |02, |01, respectively, in each bank, which will provide the desired frequency.

The pulsating voltage on the grid or control electrode of the tube V2 results in a pulsating current in the plate circuit of that tube which begins at the terminal 58 and includes the contact 38 and the movable switch 25, the conductor 93, the resistor 95 and the light I9, the resistor 82 in parallel with the resistor 95 and the light I9, the movable member and the contact 44 of the switch 26, the resistance varying member 18, the parallel connected resistance 11 and relay coil 68, the plate and lament of the tube V2, and return by way of the conductor 98 to the terminal 60 between the resistors 59 and 6|.

In thus producing a pulsating current in the plate circuit of the tube V2, the light I9 is caused to flicker at the frequency of the pulsations and the pulsating voltage across the resistor 82 is wholly or partially impressed on the patients terminals II and I2 by the connections from the resistance varying member or voltage divider 84 to the conductor 86, the multi-point switch I8, and from that switch to the appropriate terminal of the current meter I1, the conductor 81 and the terminal I I; and by the connections from the terminal 92 to the conductor 9|, the Contact 36 and the movable switch member of the switch 24, the conductor 89 and the terminal I2.

While that pulsating current in the plate eircuit of the tube V2 during each cycle is increasing, it energizes the relay coil 68 which therefore tends to hold the relay contacts 13 and 14 closed for charging the condenser III and for discharging the condenser I I4, respectively. As the charge of the condenser III increases during each cycle the plate-to-filament resistance of the tube V2 increases, which causes the current in the plate circuit of that tube, and hence the current in the patients circuit to decrease. Meanwhile, due to the increasing resistance of the plate circuit of the tube V2, the current in the plate circuit of the tube V3 will be increasing. since that latter circuit is in parallel with the former circuit. The plate circuit of the tube V3 for the modality under discussion, extends from the terminal 58 to the contact 38 of the switch 25, the movable member of that switch, the conductor 93. the terminal 92, the resistor 83, the contact 48, and movable switch member of the switch 21, the resistance varying member 8|, the parallel connected resistance 19 and relay coil 69. the plate and lament of the tube V3 and the return conductor 98.

It will be observed for this modality that the switch 28 is open so that the light 2| is not energized, and that the movable switch member of the switch 24 is engaging the contact 36 so that the voltage across the resistor 83 is not impressed on the patients terminals. As the current in the plate circuit of the tube V2 decreases, and as the current in the plate circuit of the tube V3 increases, the relay coils 68 and 69 become deenergized and energized respectively so that the relay contacts 15 close, permitting the discharge of the condenser III, and the relay contacts 16 close, permitting the charging of the condenser II4, the other relay contacts 13 and 14 being opened at this time.

As the condenser III discharges, the plate-tofllament resistance of the tube V2 decreases, and as the charge of the condenser II4 increases, the plate-to-lament resistance of the tube V3 increases. 'Ihe plate current of the tube V2 therefore will increase and the plate current of the tube V3 will decrease again, causing the relay coil 68 to be energized, and causing the deenergization of the relay coil 69 whereby to return the relay contacts 13 to 16, inclusive, to the respective positions shown in Fig. 4. That cycle will be repeated so that the voltage across the resistance 82 will be of constant polarity and pulsating at a frequency which is variable in accordance with the particular resistance |02, |01 selected, and which will be visibly indicated by the flickering of the light I9.

(c) Slow sinusoidal This modality is sometimes called reverse polarity galvanic wave, and results from an alternating voltage of relatively low frequency. In manipulating the selector means I4 to obtain this modality as indicated at c in Fig. 5, the switches 23, 25, 26, and 21 are set as in the preceding modality; the movable switch member of the switch 24 is moved into engagement with the contact 35; and the movable switch member of the switch 28 is moved to engagement with the contact across the resistor across the resistor 82, is divided and impressed on the patients terminals and I2 when the voltage control means I5 is operated. The tubes V2 and V3, the relay coils 68 and 69, the relay contacts 13, 14, 15, and 16, the resistors |02 and |01, and the condensers III and I|4 operate as described above in connection with galvanic wave, and since the voltage across the resistor 83 is of opposite polarity from that across the resistor 82, the resulting current wave will internately at the frequencies of the current waves of the respective polarities, whereby to indicate the frequency of the positive waves, the frequency of the negative waves, and hence the polarity of the waves.

(d) Pulsatz'ng direct current T'his modality is obtained by manipulating the selector operating means I4 to set the switches 23 to 28, inclusive, in the positions indicated at d in Fig. 5, and results from a voltage of constant polarity pulsating relatively rapidly as compared with the pulsations of galvanic Wave.

For this modality, the pulsating or unltered output of the rectifier R is impressed on the line conductors |20 and |23. 'Ihe line conductor |20 is connected to the terminal 6| of the resistor 6I. The terminal 60 of that resistor 6| is connected to the opposite side of the output of the filter F through the resistors 59 and 58 and to the conductor 98. The line conductor |23' is connected to the conductor 93 by way of the con- T'hus the voltage impressed., 83, as well as that impressed tact 39 `and the movable switch member of the switch 25.

The plate circuits of the tubes V2 and V3 are connected in parallel across the conductors 93 and 98 as in the modality described above as galvam'c wave, but since the movable switch member of the switch 26 is in engagement with the contact 45 the conductor |34 open circuits the parallel connected resistance 11 and relay coil 88. During the operation of the apparatus for this modality, therefore, the relay coil 68 will be deenergized and the relay coil 69 will be energized, with the result that the relay contacts 15 and 16 will be continuously closed and the relay contacts 13 and 14 will be continuously open.

With the relay contacts 15 closed, the pulsating voltage of constant or unidirectional polarity on the conductor 98 is impressed on the grid or control electrode of the tube V2 by way of the conductor |25, those contacts 15, the conductor |24, the conductor |1, the movable contact member |84, the selector contact |03 and resistor |02, the common terminal |I, and the conductor 98. Thus the pulsating potential difference between the conductors 93 and 98 will result in a pulsating current of constant polarity from the conductor 93 through the resistor 82, the resistor 95 and the light |9 in parallel with the resistor 82, the contact 45 and movable member of the switch 26, the conductor |34, the plate and filament of the tube V2, and back by way of the conductor 98. The light I9 will therefore flicker at the frequency of the pulsations.

With the relay contacts 16 closed the Condenser ||4 is charged in the charging circuit already described. Thus the plate-to-lament resistance of the tube V3 is relatively great so that a relatively small current will flow from the conductor 93 through the resistor 83, the contact 48 and the movable member of the switch 21, the resistance varying member 8|, the parallel connected resistance 19 and relay coil 69, the plate and filament of the tube V3, and back by way of the conductor 98. That current Will, however, be suflicient to maintain the relay coil 69 energized to hold the relay contacts 15 and 16 closed and the relay contacts 13 and 14 open. The switch 28 being open, the light 2| will not be energized.

Since the movable member of the switch 24 is for this modality in engagement with the contact 36 the potential drop across the resistor 83 will not be applied to the terminals Il and I2. All, or a portion of the potential drop across the resistor 82, depending upon the position of the variable member 84, will, however, be impressed on those terminals through the connections already described. Thus a voltage of constant polarity, pulsating relatively rapidly, is impressed on the patients terminals and I2 for producing the modality under discussion.

(e) Pulsating direct current wave For the positions of the switches 23 to 28, inclusive, reference is made to e in Fig. 5. This modality results from. a relatively rapidly pulsating voltage of constant polarity, which gradually increases to a maximum, and gradually decreases to a minimum at a frequency or periodicity less than that of the pulsations. In other words, this modality may be considered as a combination of galvanic wave and pulsating direct current. The circuit diifers from that just described under pulsating direct current, only in that the movable member of the switch 26 engages the contact 44 whereby to include the parallel connected variable resistance 11 and the relay coil 58 in the plate circuit of the tube V2.

As thus connected, the relay coils 88 and 69 will alternately open and close the relay contacts 13 and 14, and the relay contacts 15 and 16 respectively. As described above in connection with the galvanic wave, such operations of the relay contacts 13 to 18, inclusive, result in a relatively low frequency pulsating voltage being applied t.; the resistor 82. Since, however, the voltage applied to the grid or control electrode of the tube V2 is derived from the same source as that described under pulsating direct current, the voltage applied to the resistor 82 in the plate circuit of that tube is also pulsating relatively rapidly. The resultant voltage effect is then a series of relatively rapid pulsations which gradually increase in amplitude to a maximum, and then gradually decrease in amplitude to a minimum, the rate of increase and decrease in amplitude being controlled by the frequency control means I6 as described above.

All, or a portion of that resultant voltage across the resistor 82, is impressed on the patients terminals and l2 in the manner described under pulsating direct current for producing the modality known as pulsating direct current wave.

(f) Pulsatz'ng sinusoidal wave For the positions of the switches 23 to 28, inclusive, to produce this modality, see f in Fig. 5. This modality is the result of a relatively rapidly pulsating voltage which, at a frequency less than that of the pulsations, gradually increases in amplitude to a maximum and gradually decreases to a minimum, reverses polarity, and gradually increases to a maximum and gradually decreases to a minimum at the reverse polarity. In other words, this modality may be considered as a combination of slow sinusoidal and pulsating direct current. The circuit differs from that just described under pulsating direct current wave, in that the movable member of the switch 24 is in engagement with the contact 35 and the movable member of the switch 28 is in engagement with the contact 5|.

Thus, as in slow sinusoidal, the voltage across the resistor 82 will cooperate with the Voltage of opposite polarity across the resistor 83 to produce an alternating voltage of relatively low frequency. Since, however, the Voltage applied to the grids or control electrodes of the tubes V2 and V3 is derived from the same source as that described under pulsating direct current, the voltages applied to the resistors 82 and 83 in the plate circuits of the tubes V2 and V: are also pulsating relatively rapidly. The resultant voltage effect is therefore a plurality of series of relatively rapid pulsations of one polarity, which gradually increase in amplitude to a maximum and then decrease in amplitude to a minimum, and which alternate with a plurality of series of such pulsations at the opposite polarity, that gradually increase in amplitude to a maximum, and then gradually decrease in amplitude to a minimum. The rate of increase and decrease in amplitude of the resultant voltage effect across the resistors 82 and 83 is controlled by the frequency control means I6 as already described.

In this modality the lights |9 and 2| being respectively in parallel with the resistors 32 and 83, will flicker alternately to indicate the frequency and polarity of the pulsations. All or a portion of the resultant voltage across the resistors 82 and 83 is impressed on the patients terminals II and l2 in the manner described under slow sinusoidal.

(y) Oscillating current This modality results from a voltage of constant polarity which oscillates at a frequency that is relatively rapid as compared with the frequency o5? pulsating direct current. By reference to g in Fig. 5, it will be observed that the circuit made by the switches 23 to 28 for this modality is practically the same as that for pulsating direct current, except that the oscillator O provides the source of energy, since the movable member of the switch 25 is in engagement with the contact 31, and except that the parallel connected resistor 'I9 and relay coil 69 are directly connected in series in the plate circuit of the tube V3 by virtue of the engagement` between the movable switch member and the contact 41 of the switch 21.

With the movable member of the switch 25 contacting the switch contact 21, the oscillator O energizes the conductors 93, 98, and II9. As in pulsating direct current, the plate circuits of the tubes V2 and V3 are connected in parallel across the conductors 93 and 98; and the movable member of the switch 26 engages the contact 45, thus causing the conductor |34 to short circuit the parallel connected resistance 11 and relay coil 68. During the operation of the apparatus for this modality, therefore, the relay coil 68 will be deenergized and the relay coil 69 will be energized with the result that the relay contacts 15 and 16 will be continuously closed, and the relay contacts 13 and 14 will be continuously open.

The grids or control electrodes of the tubes V2 and V3 are energized from the conductors 98 and l I9 as already described, and therefore the oscillating voltage between the conductors 93 and 98 will cause an oscillating current to ow in the plate circuits of the tubes V2 and V3 including the resistors 82 and 83. Due to the fact that the movable member of the switch 24 is in engagement with the contact 36, only the potential drop across the resistor 82 is utilized for energizing the patients terminals II and I2 as explained under pulsating direct current. The voltage across the patients terminals being derived from that across the resistor 82 caused by the oscillating current therein, will be oscillating. Since the switch 28 is open, the light 2l will not be energized, but the light I9 in parallel with the resistor 82 will flicker at the frequency of oscillations of the current.

(h) Oscillating wave The positions of the switches 23 to 28 for this modality are shown at h in Fig. 5. This modality results from a voltage oscillating as in oscillating current described above, and the oscillations are of constant polarity which gradually increase in amplitude to a maximum and then gradually decrease in amplitude to a minimum at a frequency less than the frequency of oscillation. In other words, this modality may be considered as a com- `bination of galvanic wave and oscillating current. The circuit differs from that just described under oscillating current, only in that the movable member of the switch 26 has been moved to engagement with the contact 44 for connecting the parallel connected resistance 11 and relay coil 68 in the plate circuit of the tube V2.

Except for the source of energy, the circuit for this modality is substantially identical with that described under pulsating direct current wave. The current oscillations in the plate circuit of the tube V2 will therefore gradually increase in amplitude to a maximum, and thereafter decrease in amplitude to a minimum at a frequency which is variable by the frequency control means I6. 'I'he oscillating wave current will produce an oscillating Wave voltage drop across the resistor 82 and, as in pulsating direct current wave, all or a part of that oscillating wave voltage drop across the resistor 82 is impressed on the patients terminals for producing oscillating wave. The light I9 is in parallel with the resistor 82 and will therefore flicker at the frequency of oscillations.

(i) Oscillating sinusoidal wave See i in Fig. 5 for the positions of the switches 23 to 28 to produce this modality. This modality results from a voltage oscillating as in oscillating current, and the oscillations gradually increase in amplitude to a maximum and gradually decrease in amplitude to a minimum, reverse polarity, and gradually increase to a maximum and decrease to a minimum amplitude at the reversed polarity. In other words, this modality may be considered as a combination of slow sinusoidal and oscillating current. The circuit differs from that just described for oscillating wave, in the same respects that the circuit for pulsating sinusoidal wave differs from that for pulsating direct current wave.

Thus the oscillating voltage impressed on the patients terminals will have, in addition to the relatively rapid oscillating effects, the sinusoidal characteristics with a periodic reversal of polarity as described above under pulsating sinusoidal wave. The lights I9 and 2I will flicker alternately at the frequencies of the respective polarities to indicate polarity and frequency.

(i) Alternating current The positions of the switches 23 to 28, inclusive, for this modality are shown at j in Fig. 5. To produce this modality, the movable members of the switches 26 and 21, respectively, engage the contacts 46 and 49, whereby to close a circuit from one terminal of the secondary transformer winding 54 to the line conductor I22, the contact 46 and the movable member of the switch 26, the resistor 82, the common terminal 92, the resistor 83, the movable member and the contact 49 of the switch 21, the resistor I2 I the conductor I I9, and back to the center tap of the secondary transformer winding 54 by way of the conductor |28. Thus the alternating voltage induced in the secondary winding 54 of the transformer T will produce an alternating current in the circuit just traced.

As a result of that alternating current, the voltage drop across the resistors 82 and 83 will be alternating. All, or a portion of that alternating voltage drop, may be impressed on the patients terminals I I and I2 by operating the voltage control means I5 to adjust the resistance varying members 84 and 85 which are electrically connected to the patients terminals I I and I2 respectively in the manner described under slow sinusoidal above. Since the switch 28 is closed, the lights I9 and 2I are in parallel with the resistors 82 and 83 and will therefore flicker alternately at the frequency of the alternating current.

Thus the energy from a conventional source may be electronically, as distinguished from mechanically or electro-mechanically, converted into various modalities for use in physiotherapy, whereby to permit of accurate and reliable control and to secure uniform results at the respective selector positions, and whereby to simplify the construction, maintenance, and control of electrophysiotherapeutic apparatus for accomplishing such results.

While I have described a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes Within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electrotherapeutic apparatus, comprising a single pair of patients terminals, a source of alternating current, thermionic means for converting the energy from said source into various wavy modalities of electrophysiotherapy, and selector means for selectively modifying the operation of the thermionic means and thereby selectively applying any of said modalities to said patients terminals, said means including a condenser for controlling the action of said thermionic means, a relay for effecting the charging and discharging of the condenser, and a variable resistance for controlling the periodic time of the operation of said relay.

2. An electrotherapeutic apparatus, comprising a single pair of patient's terminals, a source of alternating current, thermionic means for converting the energy from said source into various wavy modalities of electrophysiotherapy, selector means for selectively modifying the operation of the thermionic means and thereby selectively applying any of said modalities to said patients terminals, said means including a condenser for controlling the potential of a control electrode and thereby the output of said thermionic means, a variable resistance for varying the time required to charge said condenser, and a relay for effecting the charging and discharging of said condenser, and means for indicating the frequency and polarity of the current in the selected modality.

3. An electrotherapeutic apparatus. comprising a source of alternating current, a source of pulsating current, a source of oscillating current, a source of galvanic current, means for converting the currents from said sources into electrophysiotherapeutical modalities known respectively as alternating current, pulsating direct current. scillating current, and galvanic current, thermionic means for periodically varying the current amplitudes of the last three mentioned modalities to convert them into electrophysiotherapeutical modalities known respectively as pulsating direct current wave and pulsating sinusoidal wave; oscillating wave and oscillating sinusoidal wave; and galvanic wave and slow sinusoidal, and selector means controlling the current sources, the converting means, and said thermionic means for selectively producing the desired modality, said means including a condenser for controlling the potential of a control electrode and thereby the output of said thermionic means, and means for selectively varying the time required to charge and discharge said condenser.

4. An electrotherapeutic apparatus having a single pair of output terminals, comprising a source of alternating current, means for converting energy from said source into the electrophysiotherapeutical modality known as alternating current, thermionic means for converting the energy from said source into the electrophysiotherapeutical modalities known as galvanic; pulsating direct current; and oscillating current,

thermionic means for converting the last mentioned modalities into the modalities respectively known as galvanic wave and slow sinusoidal; pulsating direct current wave and pulsating sinusoidal wave; and oscillating Wave and oscillating sinusoidal wave, and means for selectively causing the production of said modalities and applying them to said output terminals, said means including a condenser for controlling the potential applied to a control electrode and thereby the output of said thermionic means, and a relay for controlling the charging and discharging of said condenser.

5. An electrotherapeutic apparatus having a single pair of output terminals, comprising a source of alternating current, means for converting energy from said source into the electrophysiotherapeutical modality known as alternating current, a pair of thermionic means for converting energy from said source into the electrophysiotherapeutical modalities known as galvanic, galvanic wave, slow sinusoidal, pulsating direct current, pulsating direct current wave, pulsating sinusoidal wave, oscillating current, oscillating wave, and oscillating sinusoidal wave, and means for selectively causing the production of said modalities and applying them to said output terminals, said means including a pair of condensers for controlling the potentials applied to control electrodes and thereby the outputs of said thermionic means, and a relay for controlling the charging and discharging of said condensers in alternation.

6. In an electrotherapeutic apparatus having a source of electrical energy and output terminals, an electrical circuit electrically interposed between said source and said terminals for converting the energy from said source into a desired modality, said circuit including a thermionic tube ha "ing plate, lament, and control electrodes, a relay coil in series with said plate electrode, a condenser having charging and discharging branch circuits electrically connected with the control electrode of said tube, and contact means in each of said branch circuits and operable by said relay coil for alternately charging and discharging said condenser thereby cyclically varying the amplitude of the voltage applied to said control electrode whereby cyclically to vary the amplitude of the current in said electrical circuit.

7. In an electrotherapeutic apparatus having a source of electrical energy and output terminals, an electrical circuit electrically interposed between said source and said terminals for converting the energy from said source into a desired modality, said circuit including a thermionic tube having plate, lament, and control electrodes, a relay coil in series with said plate electrode, a condenser having charging and discharging branch circuits electrically connected with the control electrode of said tube, and contact means in each of said branch circuits and operable by said relay coil for alternately charging and discharging said condenser thereby cyclically varying the amplitude of the voltage applied to said control electrode whereby cyclically to vary the amplitude of the current in said electrical circuit, and means electrically connected with said condenser for controlling the rate of charging and discharging whereby to control the frequency of the amplitude variations of current in said electrical circuit.

8. In an electrotherapeutic apparatus, the combination with input and output terminals, a plurality of branch circuits interposed between the input and output terminals for converting electrical energy into a desired modality, a said branch circuit including a thermionic tube having plate, filament, and control electrodes and a relay coil in series with said plate electrode, another said branch circuit being in parallel with the rst said branch circuit and including a thermionic tube having plate, filament, and control electrodes and a relay coil in series with the last said plate electrode, a condenser having charging and discharging branch circuits electrically connected with the first said control electrode, another condenser having charging and discharging branch circuits electrically connected with the second said control electrode, and contact means in each of said last mentioned branch circuits and operable by said relay coils for alternately charging and discharging said condensers, thereby cyclically varying the amplitude of the voltages applied to said control electrodes whereby cyclically to vary the amplitude of the current in the parallel branch circuits.

9. In an electrotherapeutic apparatus, the combination with input and output terminals of a plurality of branch circuits interposed between the input and output terminals for converting electrical energy into a desired modality, a said branch circuit including a thermionic tube having plate, filament, and control electrodes and a relay coil in series with said plate electrode, another said branch circuit being in parallel with the first said branch circuit and including a thermionic tube having plate, filament, and control electrodes and a relay coil in series with the last said plate electrode, a condenser having charging and discharging branch circuits electrically connected with the first said control electrode, another condenser having charging and discharging branch circuits electrically connected with the second said control electrode, and contact means in each of said last mentioned branch circuits and operable by said relay coils for alternately charging and discharging said condensers, thereby cyclically varying the amplitude of the voltages applied to said control electrodes whereby cyclically to vary the amplitude of the current in the parallel branch circuits, and means electrically connected with each of said condensers for controlling the rate of charging and discharging whereby to control the frequency of the amplitude variations of current in said parallel branch circuits.

10. An electrotherapeutic apparatus for operation from an alternating current source and comprising a transformer for connection to the source, a current rectifier connected to the transformer, a filter connected to the rectier, an oscillator connected to the filter, a pair of thermionically controlled current modifiers, a pair of patients terminals, and a gang selector switch for varying the connections between the transformer, rectifier, filter, oscillator, current modifiers and patients terminals selectively to deliver to the patients terminals a steady unidirectional current, a pulsating unidirectional current, a reverse polarity current having a frequency less than the frequency of the source. a pulsating current having a frequency greater than the frequency of the source and an alternating current of the same frequency as the source.

11. An electrotherapeutic apparatus for operation from an alternating current source and comprising a transformer, a rectifier, an oscillator, a pair of patients terminals, and means for periodically modifying the current delivered from the oscillator to the patients terminals, said means including a thermionic tube having a grid for controlling the output thereof, a condenser connected to the grid, a relay for periodically charging and discharging the condenser, and a variable resistance for varying the rate at which the condenser is charged.

l2. An electrotherapeutic apparatus for operation from an alternating current source and comprising a transformer for connection to the source, a current rectifier, a current filter, an oscillator, a pair of patients terminals, thermionically controlled means for modifying the current delivered to the patients terminals from the rectifier, from the lter and from the oscillator, a polarized relay for periodically varying the action of the thermionically controlled means, and a series of simultaneously operable manual switches for selectively controlling the action of the thermionically controlled means and the action of the relay.

13. An electrotherapeutic apparatus for operation from an alternating current source and comprising a transformer for connection to the source, a current rectifier, a filter, an oscillator, a pair of patients terminals, a plurality of simultaneously actuated switches under manual control for selectively associating the transformer, rectifier, filter and oscillator to produce unidirectional constant and unidirectional pulsating and oscillating current as desired, a pair of thermionic tubes for modifying any current so produced, and means acting periodically to vary cyclically and alternately the modifications produced by the tubes to impress upon the patients terminals a. recurring series of modified current waves.

14. An electrotherapeutic apparatus, including in combination, output terminals, a source of current and means interconnecting said source and terminals for transforming said current into a wavy modality of electrophysiotherapy, said means including a circuit interconnecting said source and terminals, thermionic means in said circuit having a control electrode, the potential of which is adapted to be varied to control the conductivity thereof, and automatically and periodically operating means including a relay for Varying the potential applied to said electrode, thereby to vary the conductivity of said thermionic means.

15. An electrotherapeutic apparatus, including in combination, output terminals, a source of current, and means interconnecting said source and terminals for transforming said current inte a wavy modality of electrophysiotherapy, said means including a circuit interconnecting said source and terminals, thermionic means in said circuit having a control electrode, the potential of which is adapted to be varied to control the conductivity thereof, a condenser connected to said control electrode, resistors adapted selectively to be placed in circuit with said condenser and control electrode, and periodically operating relay means for alternately charging and discharging said condenser through a selected resistor, thereby cyclically to vary the amplitude of the potential applied to said control electrode and cyclically to vary the amplitude of the current supplied to said output terminals.

JOSEPH H. DOBERT.

CII 

